1. Field of the Invention
The present invention relates to propylene resin compositions which have improved impact resistance at both room temperature and low temperatures, which have excellent property balance between rigidity and impact resistance, and which are useful for exterior and interior automotive trims, exterior trim parts of electrical apparatus, and the like.
2. Related Art
A propylene resin has high rigidity and high moldability, and is inexpensive. Its use is therefore expanding recently at an increasing tempo in the fields of exterior and interior automotive trims, for instance, bumpers, manuals, front grilles and interior panels, exterior trim parts of electrical apparatus, and the like.
However, even such a polypropylene resin has a shortcoming in that its impact resistance is still insufficient depending upon its use. In order to overcome this shortcoming, a polypropylene resin has conventionally been blended with a rubbery elastic material such as ethylene-propylene copolymer rubber, ethylene-butene copolymer rubber or ethylene-propylene-diene copolymer rubber.
It is, however, difficult to obtain a composition which has excellent property balance between impact resistance and rigidity by blending a propylene resin with the above rubbery elastic material with the intention of solving the aforementioned problem while retaining high rigidity which is an advantageous property inherent to a polypropylene resin.
An object of the present invention is to provide a propylene resin composition which has excellent property balance between impact resistance and rigidity by improving its impact resistance while retaining its high rigidity which is an advantageous property of a polypropylene resin.